


Sidekick Effect

by TearsAndFlowers



Series: Shadow Boom AU [1]
Category: Sonic Boom (Cartoon)
Genre: Alternate Universe - Character Swap, Gen
Language: English
Status: Completed
Published: 2018-07-11
Updated: 2018-07-11
Packaged: 2019-06-08 15:04:37
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,231
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15245931
Author URL: https://archiveofourown.org/users/TearsAndFlowers/pseuds/TearsAndFlowers
Summary: When Tails is injured during a battle with Eggman, Shadow begins pushing Tails and the others away. Tails is determined to find out why.(Alternate universe where Sonic and Shadow's roles are switched. Re-imagining of "The Sidekick".)





	Sidekick Effect

**Author's Note:**

> "Sidekick effect" is a play on "side effect"; I'm bad with titles, so that's the best I could come up with.
> 
> Anyway, since I'm still struggling with "By Your Side", I decided to work on this AU some more. Hope you enjoy!

" _Tails!_ "

Shadow watched in horror as Tails' plane crashed into the ground. He turned around to see Eggman using an electromagnet to pick up his robot, which was currently trapped under a pile of rocks. Rage coursed through Shadow's veins.

Before Eggman even knew what was happening, he, his Eggmobile, and his robot were sent hurtling through the sky.

Shadow, after taking a moment to calm down, teleported himself to the site of the plane crash. Smoke was rising from the ruined plane. Tails was still inside, and he wasn't moving. A knot formed in Shadow's stomach. Images flashed in his mind; images of being trapped inside of an escape pod, his desperate cries being ignored, only able to watch helplessly as…

Shadow shook his head. Now was not the time to think of that.

Once he'd freed Tails from the wreckage, he pressed his ear against Tails' chest. There were a few tense moments, before he heard it: a heartbeat. Shadow breathed a sigh of relief. Gently, he scooped Tails up in his arms.

"I'm sorry, Tails,” he said softly, as he carried his friend home. “I promise, nothing like this will ever happen to you again."

* * *

Shadow leaned with his back against the wall of Tails' house, glancing periodically at the unconscious fox on the couch. He pushed away the anxiety that tried to creep into his mind, reassuring himself that everything would be fine.

Finally, he heard a quiet groan. He looked, and sure enough, Tails was awake. Shadow rushed to his side.

"Ugh...what happened?" Tails asked.

"You were injured in our most recent battle with Eggman," Shadow explained.

"Oh, yeah..." Tails sat up as he recalled the events. "Well, I'm feeling much better now. I'm ready to get back in action!"

“About that…” Shadow averted his gaze. “I’ve been thinking. I think it would be best if you took a break.”

“A break?”

Shadow began walking towards the door. “Yes. You should rest for a while.”

“But I feel fine!” Tails insisted.

Shadow opened the door. “How else can I put this? You’re fired.”

And with that, he left, closing the door behind him.

“Oh, okay,” Tails said.

There was a pause.

“...wait, what?”

* * *

Shadow sighed. He felt terrible about firing Tails from being his sidekick, and a small part of him wondered if he’d made the right choice.

_It’s for the best,_ he told himself. _He’ll be safer this way._

“Hey, Shadow!” Amy’s voice greeted. “How is Tails? Is he okay?”

Amy, Knuckles, and Sticks had all been waiting outside.

“He’ll be fine,” Shadow replied, not looking any of his friends in the eye. He didn’t stop walking.

“Hey, where are you going?” Knuckles asked.

Shadow didn’t respond. Before anyone else could say anything else, he’d already teleported away.

* * *

For the next couple of weeks, Shadow insisted on fighting Eggman alone. His friends were all concerned, but every time they tried to talk to him, he told them to go away. Every time they tried to help him fight off Eggman’s robots, he yelled at them to back off. Even when they were all hanging out together, he felt distant, like he wasn’t really there.

After putting up with this for two weeks, Shadow’s friends decided that enough was enough.

“Okay, that’s it!” Sticks said. “I don’t care if he wants to talk or not; we’ve got to stop this _now_.”

“But how?” Knuckles asked. “He won’t listen to us!”

Amy turned to Tails. “You’re his best friend. Maybe you can get him to talk.”

“He hasn’t even let me see him since he fired me,” Tails reminded her.

“I know, but you have to try. Please Tails, you’re the only one who has a chance of getting through to him.”

“Alright,” Tails finally agreed. “I’ll try. Wish me luck, guys.”

* * *

_Shadow trudged through the pouring rain, desperately searching for shelter. He was cold, wet, and alone, with nowhere to go._

_"Hey!" a child's voice shouted nearby. "Over here!"_

_Shadow turned around, and saw a young fox standing in the doorway of a building; the building looked like a workshop of some kind. The kid couldn't have been any older than five._

_"Hurry, get inside!" the fox called._

_Shadow didn't hesitate._

_Once Shadow was inside, the fox rushed to fetch him a towel. As Shadow dried himself off, the fox stared at him curiously._

_"What were you doing out in the rain?" he asked._

_"I don't want to talk about it," Shadow mumbled._

_"Oh."_

_There was an awkward silence. Shadow finished drying himself off and handed the towel back. As he looked around, he noticed several broken machines lying around, all of which were very complex in design._

_"What is all of this?" he asked._

_"Oh, those are mine," the young fox replied. "I'm an inventor! Though I'm not very good at it yet..."_

_"Still impressive for someone who's still learning how to read," Shadow pointed out._

_The fox child beamed. "You really think so?"_  
_Then, looking quite proud of himself, he added, "And for the record, I've been able to read since I was three. I can read fifth grade level books now!”_

_Shadow’s eyes widened in astonishment. “Really now?”_

_“Yup!” the fox replied. “My parents said that I'm ‘wise beyond my years’!"_

_Shadow noticed the fox’s smile falter, and decided to ask the question that had been lingering in the back of his mind since he stepped inside the house. "Where are your parents, anyway?"_

_The fox looked down at the floor, his ears drooping as tears welled up in his eyes. "Th-they...they died...months ago..."_

_"Oh..." Shadow couldn’t help feeling sympathy for the poor child. "So who do you live with, then? An uncle or aunt? A cousin? A friend of your parents?"_

_"Nobody. I live alone. The villagers, well...they don’t really care about anyone but themselves. I have to fend for myself."_

_Shadow was shocked. "You...you've been taking care of yourself this whole time?"_

_The fox nodded, still not making eye contact as he sniffled. Shadow was both impressed by the fact that such a young child could look after himself, and appalled by the fact that this was necessary in the first place. What kind of heartless monsters would leave an orphaned five year old to fend for himself?_

_"What about your parents?" the fox asked, wanting to change the subject. "Aren't they going to be worried about you?"_

_"I never met my parents," Shadow admitted. "I don't even know who they were."_

_"Oh."_

_There was another long silence, the only sound being the pouring rain outside._

_"So...do you have a home?" the fox asked._

_Shadow shook his head. "No. Not anymore."_

_"Well...you can stay here in the village, if you'd like. There's a nice little shack that nobody’s using; I'm sure no one would mind if you decided to live there! Though you can stay here tonight."_

_“Well, I…” Shadow paused, seeing the puppy dog eyes that the child was giving him. How could he say no to that face? He sighed, giving in._  
_"Alright, I'll consider it. As for staying the night…” He glanced outside the window, realizing that the rain wasn’t letting up anytime soon. “...I think I'll take you up on that offer."_

_The fox's face brightened. "Really?"_

_Shadow nodded. The fox cheered. Shadow then noticed two peculiar things: first, that the fox had two tails, and second, that he was currently using said tails to propel himself into the air like a helicopter._

_"What's your name, kid?" Shadow asked, as the child lowered himself back to the ground._

_"My name is Miles," the fox replied. "I don't really like it, though."_  
_Then an idea came to him. "Hey, maybe you can give me a new name," he suggested._

_"O-oh, um..." Shadow was caught off guard. He was too proud to admit it, but nicknaming was something he was terrible at._

_Seeing Miles' hopeful face, Shadow scrambled to think of answer. He glanced at the fox’s two tails._

_"Uh...Tails?" It was the first thing that popped into his head._

_Tails smiled. "I like it."_

_Shadow suppressed a sigh of relief._

_"So, what's your name?" Tails asked._

_"Shadow. Shadow the Hedgehog."_

_"Nice to meet you, Shadow."_

_Suddenly, there was a flash of light outside, followed by the loud sound of thunder. Tails screamed, curling up and hiding himself behind his tails._

He's scared of thunder, _Shadow realized._

_Not sure what to do, he walked over to Tails and sat down beside him._

_"It's alright. The thunder can't hurt you."_

_Tails peeked out from behind his namesakes. "I-I know. I just..." He whimpered._

_Shadow patted him on the head. "Don't worry. As long as I’m here, no harm will come to you.”_

_Tails looked up at him, his eyes shimmering. “Promise?”_

_“I promise.”_

* * *

When Tails found Shadow, Shadow was about to fight Eggman. Shadow, Eggman, and one of Eggman’s robots were all standing on the frozen lake.

Shadow shook his head. “You still haven’t changed that thing’s name?”

“No,” Eggman replied. He grinned. “However, I don’t need to now. Because now, Burnbot _can_ burn things!”

Burnbot fired two fireballs, which created a ring of fire around Shadow. The ice began to melt and crack around him. Shadow teleported to another part of the lake just before the ice gave way. Burnbot fired one of its claws at Shadow, the claw turning into a buzzsaw. Shadow dodged it, and it crashed into the ice, cracking it further. Shadow teleported away again. Burnbot fired its other claw at him, this claw also turning into a buzzsaw. Like with the first attempt, it completely missed Shadow, and broke more of the ice.

Shadow and Burnbot repeated these actions several times, until Shadow had nowhere else to stand. The ice gave way beneath him, and he slipped into the cold water below. As soon as he rose back to the surface, he swam towards the nearest piece of ice and grabbed on. However, the chunk of ice began to flip up, causing Shadow to lose his grip. He fell back into the water, the ice chunk flipping completely upside down and on top of him.

Tails gasped. Without even stopping to think, he was already rushing towards the lake. He dived into the water below, and looked around for Shadow. After a few tense moments, he spotted him. Shadow was trapped under the ice; he couldn’t hold his breath much longer, as evidenced by the growing panic in his eyes. Tails swam over to him and grabbed Shadow from behind. He used his tails as a propeller to push Shadow and himself above the surface of the water, and onto a more stable chunk of ice. Shadow gasped for air.

“T...Tails? What are you doing here…?”

Tails didn’t respond. He reached into his hammerspace, pulling out a bazooka-like weapon. Aiming it towards Burnbot, he fired. It launched a missile at Burnbot, the robot immediately exploding on impact. Bits of it went flying everywhere, the head landing right next to Eggman. Tails grinned; his invention had worked! Then it exploded in his hands. He sighed in frustration.

Eggman growled. “I'll be back! With a new robot! Who has an accurate name! And super laser eyes! And he'll feed me ham! _Evil_ ham.”

And with that, Eggman flew off in his Eggmobile.

Tails grabbed Shadow’s arms from behind, and used his tails to propel himself into the air. He flew Shadow to the shore and set him down, before gently landing next to him.

Tails got right to the point. “Why did you fire me?”

Shadow avoided eye contact, staying silent.

“Come on, Shadow. You’ve always been able to talk to me. What’s going on?”

Shadow still didn’t look up. “Go home, Tails.”

Tails’ patience ran out. “I’ve had enough of this, Shadow! I want answers, and I’m not going to leave you alone until I hear them! Why did you fire me? _Why do you keep pushing me away?!_ ”

“ _Because I can’t lose anyone else!_ ” Shadow blurted.

Tails took a step back in shock. “W...what?”

Shadow sighed, looking down at his feet. When he spoke again, it was in a soft voice. “I lost someone, a long time ago. Her name was Maria. She...she was like a sister to me. But then, one day…”  
He shuddered as horrible memories came flooding back to him, his voice wavering as he spoke. “She was shot. I...I couldn’t save her…I-I had to watch her die...”

Tails saddened, his ears drooping. “Shadow…I had no idea. I’m sorry.”

“So am I.” Shadow looked up. “I never wanted to fire you, or push you and the others away. I convinced myself that I was protecting all of you, but I now realize that I was only protecting myself. Can...can you ever forgive me?”

Tails walked up to Shadow. Suddenly, he threw his arms around Shadow.

“I forgive you.”

Tails kept hugging Shadow for a few moments, then let him go. “So...does this mean I get to be your sidekick again?”

Shadow cracked a small smile as he patted Tails on the head. “Of course.”

Tails smiled back. “Let’s go home.”

The two headed into the jungle, both feeling a lot better than they had in the past two weeks. It was good to be back.

**Author's Note:**

> I wasn't really sure where to put the flashback. Should I have put in earlier in the story?
> 
> Also, just to clarify some things:
> 
> -Even though Tails is canonically eight years old, he's ten in my fanfics. So the flashback scene takes place five years ago.  
> -Shadow ages naturally in this universe, and is the same age as Sonic. So he's ten years old in the flashback, and was somewhere from eight to ten when Maria died.  
> -Since Maria existed in this universe, but much later in the timeline than in the main universe, Eggman's family tree is probably completely thrown off. Oh well.  
> -EDIT: Forgot to mention, Tails' bazooka weapon is inspired by one of the weapons in the Shadow the Hedgehog game.
> 
> If there's anything else you'd like me to explain about this AU, let me know!
> 
> EDIT: Made a slight tweak to one part. Nothing major.


End file.
